Magnetic guide for tools



y 6, 1 c. s. FINNELL 2,323,319

MAGNETIC GUIDE FOR TOOLS Filed March 24, 1941 CharZes-SFz'zzneZ Z.

Patented July 6, 1943 u ilED SKATES 3 Claims.

This invention relates to gu'des for reciprocatory tools such as saws, files and the like.

The invention contemplates the use of a ma net as a guiding means for a reciprocatory tool. Various modifications of this generic idea of using a magnet as a guide for tools are illustrated in the accompanying drawing, in which Figure 1 is a rear view of the guiding magnet employed to guide an ordinary carpenters hand saw;

Fig. 2 is a plan view of the structure such as is illustrated in Fig. 1;

Fig. 3 is a detailed plan view illustrating that the magnet may be an electromagnet;

Fig. 4 is a side elevation of an ordinary hack saw carryi a guide plate adapted to cooperate with a magnet;

Fig. 5 is a plan view of the structure of Fig. 4, and;

Fig. 6 is a plan view illustrating a guide plate and support thereon, in whch a file or like tool is mounted.

Like numerals designate corresponding parts in all of the figures of the drawing.

All forms of the invention contemplate the use of a magnet or" any suitable size and shape adapted to engage with the flat, true surface of a tool itself, such as the blade of a hand saw, S, or a flat, true guide plate from which the tool is supported. Consequently, in a11 of the figures the magnet has been designated by the same reference character, 5, except that in Fig. 3 the magnet has been designated 5* because in that figure the magnet is indicated as being an electromagnet.

The magnets may be held against movement in any suitable way. In Fig. l, 5 indicates a work table. '5 a pece of wood being sawed, and 8 a suitable support for supporting the magnet from the table. The support 3 is preferably of nonmagnetic material. The magnet may be rigidly afiixed to the support 5, or it may be made separate from the support, as shown, and be mounted to turn upon a stud 9 that is carried by the support. A binding nut ltl, will, in that event, serve to bind the magnet in fixed relation to the sup port 8.

Further, the magnet may be provided with graduations ll, adapted to cooperate with the pointer l2, said pointer being carried by the support 8. The magnet is supported from the stud 9 by means of its hub-like portion 14 which embraces the stud 9 and underl es the binding nut l0. By providing the pointer and graduations cured to the rear side of its frame.

as described, and by mounting the magnet to turn upon the stud 9, this magnet guide may be caused to serve all of the functions of a mitre box. Such an arrangement will be not only much less expensive than the known forms of mitre boxes but will be more convenient to use.

In many of the known forms of mitre boxes it is necessary to thread the saw endwise through the guiding element. This is not the case with my invention, wherein the saw may be brought sidewise and toward the-magnet and be held by magnetism alone.

In Figs. 4 and 5 I have illustrated a conventional hack saw l5 having a guide plate 16 se- This plate may be secured in position by screws I l, or it may be welded to th plate l5. In any event, its

rear face It must be polished, straight and true so that it will slide easily with respect to its guide magnet 5.

In the form illustrated in Fig. 6, a like straight and true guide plate l9 adapted to be magnetically attracted by magnet 5 carries a file 2i! and functions as a holder for said file. Any suitable reciprocatory tool may be mounted in a tool holder having a flat guide surface adapted to engage a magnet as described.

From the foregoing description it will be apparent that the invention resides not only in the particular embodiments shown, but more generically in the thought of utilizing a magnet (with a simple, permanent magnet or an electromagnet) as a guide means for a tool, in such fashion that engagement of tool and magnet may be eifected by the simple lateral approach of the tool, or equivalent tool holder, toward the magnet.

While I have made frequent reference to the reciprocatory type of tools, I wish it to be understood that the invention includes the guiding of any tool suitable for use in connection with a magnetic guide whether such tool be reciprocatory, rotary, oscillatory or other wise.

Consequently, it is to be understood that the invention includes within its purview not only the particular arrangements illustrated, but such modifications thereof as fairly come within either the terms or the spirit of the appended claims.

Having described my invention, what I claim 1s:

1. The combination with a tool of a nature to cut under its longitudinal reciprocation and provided with an elongated flat, true face extending in the direction of the length of the tool and in parallelism with the stroke of the tool,

and a magnet disposed to engage said face and hold the tool against lateral movement while permitting its longitudinal reciprocation.

2. The combination with a support for work to be cut, of a reciprocatory cutting tool comprising an elongated fiat metallic surface, and a magnet mounted in such relation to the support as to attract and hold said metallic surface of the tool at a determined angle with respect to the support and Work during the reciproca- 10 tion of the tool in the act of cutting. 

